Two months ago, I have the exact same problem. The cause of this problem is dirty fuel line. One of my injector does not spray well. Once the injector is cleaned, the car idle smoothly. rendy vin 4220 >the needle seems to hover around 750 or so, and it moves around all over the > place randomly from about 450 to almost 1000, then it goes back to 750 for a > bit, then dances, then back to 750.